Nutrition, Human, Vitamin D

Vitamin D is fat-soluble, and cholecalciferol is the major active substance. Its main function is to stimulate the absorption of calcium. The natural source of vitamin D is from the action of short-wave ultraviolet light from the Sun on a derivative of cholesterol in the skin. Vitamin D also occurs in some foods. It is only when people live in high latitudes, consistently

Haldane, John Scott

Haldane developed several procedures for studying the physiology of breathing and the physiology of the blood and for the analysis of gases consumed or produced by the body. Among his most widely used devices were

Dance, Western, Experiments

Technological progress itself became the subject of dance and dancing. In the Soviet Union, there were experiments during the 1920s with dances created to express urban traffic, the accuracy of machine work, and the grandeur of skyscrapers. In Germany, the painter Oskar Schlemmer (1888–1943) realized his vision of a dance of pure, geometric form in the Triadisches Ballet performed

Dworkin, Andrea

Dworkin began writing at an early age. During her undergraduate years at Vermont's Bennington College (B.A., 1968), she became involved with the student demonstrations against the Vietnam War. Her experience in the New

Lea

County in the High Plains of southeastern New Mexico, U.S., bordered on the east and south by Texas. The northwestern area of the county is located on the Llano Estacado, or Staked Plain, above the Mescalero Escarpment at over 4,000 feet (1,200 m) above sea level; the land slopes to the southeast to under 3,000 feet. There are no streams in Lea county, which includes several dry lakes and creek

April Fools' Day

Also called  All Fools' Day  in most countries the first day of April. It received its name from the custom of playing practical jokes on this day—for example, telling friends that their shoelaces are untied or sending them on so-called fools' errands. Although the day has been observed for centuries, there are different explanations for its origin. It resembles festivals such as the Hilaria of

Amreli

Formerly  Amaravalli,   town, southwestern Gujarat state, west-central India. The town lies on the Kathiawar Peninsula, 125 miles (200 km) southwest of Ahmadabad. Primarily a commercial centre, its industries include the manufacture of khadi (coarse cotton cloth), tanning, silverworking, and cotton ginning. Amreli is served by a railway and an airfield. Chief crops of the surrounding area are millet, peanuts

Israel, Karaites

The Karaites are a Jewish sect that emerged in the early Middle Ages. Several thousand members live in Ramla, and more recently in Beersheba and Ashdod. Like other religious minorities, they have their own religious courts and communal organizations. Considered part of Jewish society, they have maintained their separate identity by resisting intermarriage and

Earth, Variation with elevation

At sea level the gradient is equivalent to -0.3086 milligal per metre;